There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

The semiconductor ZnO has gained substantial interest in the research community in part because of its large exciton binding energy (60meV) which could lead to lasing action based on exciton recombination even above room temperature. Even though research focusing on ZnO goes back many decades, the renewed interest is fueled by availability of high-quality substrates and reports of p-type conduction and ferromagnetic behavior when doped with transitions metals, both of which remain controversial. It is this renewed interest in ZnO which forms the basis of this review. As mentioned already, ZnO is not new to the semiconductor field, with studies of its lattice parameter dating back to 1935 by Bunn [Proc. Phys. Soc. London 47, 836 (1935)], studies of its vibrational properties with Raman scattering in 1966 by Damen et al. [Phys. Rev. 142, 570 (1966)], detailed optical studies in 1954 by Mollwo [Z. Angew. Phys. 6, 257 (1954)], and its growth by chemical-vapor transport in 1970 by Galli and Coker [Appl. Phys. ...

/pdf/a-comprehensive-review-of-zno-materials-and-devices-21a3zjadem.pdf

A comprehensive review of zno materials and devices

Spread Spectrum It’s not just for breakfast anymore! Don't blame me, the title is the work of this month's guest columnist, Steve Bible, N7HPR (n7hpr@tapr.org). While cruising the net recently, I noticed a sudden bump in the number of times Spread Spectrum (SS) techniques were mentioned in the amateur digital areas. While QEX has discussed SS in the past, we haven't touched on it in this forum. Steve was a frequent cogent contributor, so I asked him to give us some background. Steve enlisted in the Navy in 1977 and became a Data Systems Technician, a repairman of shipboard computer systems. In 1985 he was accepted into the Navy’s Enlisted Commissioning Program and attended the University of Utah where he studied computer science. Upon graduation in 1988 he was commissioned an Ensign and entered Nuclear Power School. His subsequent assignment was onboard the USS Georgia, a trident submarine stationed in Bangor, Washington. Today Steve is a Lieutenant and he is completing a master’s degree in computer science at the Naval Postgraduate School in Monterey, California. His areas of interest are digital communications, amateur satellites, VHF/UHF contesting, and QRP. His research area closely follows his interest in amateur radio. His thesis topic is Multihop Packet Radio Routing Protocol Using Dynamic Power Control. Steve is also the AMSAT Area Coordinator for the Monterey Bay area. Here's Steve, I'll have some additional comments at the end.

http://ieeexplore.ieee.org/iel5/5/31355/01457623.pdf

Digital communications

Fundamentals of Plasmonics.- Electromagnetics of Metals.- Surface Plasmon Polaritons at Metal / Insulator Interfaces.- Excitation of Surface Plasmon Polaritons at Planar Interfaces.- Imaging Surface Plasmon Polariton Propagation.- Localized Surface Plasmons.- Electromagnetic Surface Modes at Low Frequencies.- Applications.- Plasmon Waveguides.- Transmission of Radiation Through Apertures and Films.- Enhancement of Emissive Processes and Nonlinearities.- Spectroscopy and Sensing.- Metamaterials and Imaging with Surface Plasmon Polaritons.- Concluding Remarks.

/pdf/plasmonics-fundamentals-and-applications-4syb9877sr.pdf

Plasmonics: Fundamentals and Applications

Cr-doped strontium barium niobate has shown significant reduction in the time of response compared to previously grown Ce-doped crystals, with room temperature response times as short as 0.2 sec. The experimental photorefractive two-beam coupling gain and response time of 1% and 1.6% Cr-doped SBN:60 and 1% Cr-doped SBN:75 will be presented and compared to results in Ce-doped SBN:60. The photorefractive effect in Cr-doped SBN:60 has also shown a strong temperature dependence, with gain increasing by a factor of two when the crystal was cooled from 40 to -20° C. Significant gain enhancement was also predicted and obtained by applying a DC electric field of up to 10 kV/cm.

/pdf/photorefractive-properties-of-cr-doped-single-crystal-1f6to3ytqz.pdf

Photorefractive Properties Of CR-Doped Single Crystal Strontium Barium Niobate

A transverse Bragg resonance waveguide (14) is comprised of a waveguiding channel (22), and on at least two opposing sides of the channel two periodic index media (24); and a means for providing gain in the periodic index media. In one embodiment the waveguiding channel is planar and is sandwiched on two opposing sides by the periodic index media. In another embodiment the waveguiding channel is cylindrical and is surrounded by the periodic index media. The means for providing gain in the periodic index media is electrical or optical pumping. The periodic index media comprises a periodic lattice (18) of regions having an index of refraction distinct from the channel, such as an array of transverse holes (16) defined in a planar semiconductor substrate in which the channel is also defined, or an array of longitudinal holes defined in a cylindrical semiconductor fiber in which the channel is also longitudinally defined.

Traverse bragg resonance lasers and amplifiers and method of operating the same

We demonstrate that the simple rate equations do not satisfactorily account for the chirp of DFB lasers and describe an experimental technique that determines it precisely using propagation in dispersive fiber. Implications for high-speed lightwave systems are considered.

Precise measurement of laser chirp and application to simulation of lightwave systems

The feedback sensitivity of a high coherence silicon/III-V laser is quantified using an interferometer. High fringe visibility is maintained up to at a reflectivity of −21 dB, a 10 dB improvement compared to a high end commercially available DFB laser.

Optical feedback sensitivity of heterogeneously integrated silicon/III-V lasers

The mode stabilization behavior of the buried active waveguide with lateral diffused junction is theoretically investigated. The study shows that for an active waveguide of width around 5 μm with a lateral diffused junction in the middle, the single fundamental transverse mode is preferred as the injection level is raised. The theoretical results are found to be in good agreement with experimental results observed in the groove transverse junction InGaAsP/InP laser.

/pdf/mode-stabilization-mechanism-of-buried-waveguide-lasers-with-3zdxawaict.pdf

Amnon Yariv

Papers

Photorefractive Properties Of CR-Doped Single Crystal Strontium Barium Niobate

Traverse bragg resonance lasers and amplifiers and method of operating the same

Precise measurement of laser chirp and application to simulation of lightwave systems

Optical feedback sensitivity of heterogeneously integrated silicon/III-V lasers

Mode stabilization mechanism of buried-waveguide lasers with lateral diffused junctions